.container {
    width: 100%;
    height: 100%;
    --color: #E1E1E1;
    background-color: #F3F3F3;
    background-image: linear-gradient(0deg, transparent 24%, var(--color) 25%, var(--color) 26%, transparent 27%,transparent 74%, var(--color) 75%, var(--color) 76%, transparent 77%,transparent),
    linear-gradient(90deg, transparent 24%, var(--color) 25%, var(--color) 26%, transparent 27%,transparent 74%, var(--color) 75%, var(--color) 76%, transparent 77%,transparent);
    background-size: 55px 55px;
    margin: 0;
    padding: 0;
}